Some web sites and other types of interactive systems implement services for generating customized content suggestions for items stored or represented in a data repository. One common application for such services involves suggesting products for purchase, rental, subscription, viewing, or some other form of consumption. For example, some e-commerce web sites provide services for suggesting products to users based on their respective purchase histories, rental histories, product viewing histories, item ratings, and/or other behaviors. Such services are also used to suggest web sites, news articles, users, music and video files, and other types of items.